The extraction and the removal of Cd(II) using polymer inclusion membrane containing symmetric room temperature ionic liquid as ion carrier

Since cadmium is a hazardous material for environment, various techniques have been developed for safe removal of cadmium. Among these techniques, ionic polymer inclusion membranes (IPIMs) have a higher membrane structural stability that can be used to separate and recover cadmium ions with a higher selectivity. Also, the ion transport capacity of IPIMs can be further increased by selecting suitable ion carriers and plasti-cizers. In this study, preparation of IPIMs was accomplished by selecting newly synthesized symmetric and having different alkyl chain room temperature ionic liquids as ion carriers for selective the separation of cad-mium from iodide-containing acidic solutions. The highest mass transport was determined as 0.958 & mu;mol s-1 cm-2 from 25 mg L-1 and 2.02 & mu;mol s-1 m- 2 from 75 mg L-1 Cd(II) solution, respectively, when using the optimized IPIM containing 24.97% (w/w) 2-nitrophenyl octyl ether as plasticizer and 35.12% (w/w) 1,3-decyl-1 H-imidazol-3-ium bromide as carrier. The mass transport of cadmium was determined as 0.567 & mu;mol s-1 m- 2 in the presence of Cr3+, Fe2+, Co2+, Ni2+ and Zn2+. Surface analyses were explored by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), while the structural analysis was carried on by Fourier infrared spectroscopy (FTIR) before/after Cd transport experiments.

Automated summary

Various techniques have been developed for safe removal of cadmium due to its hazardous nature to the environment. Ionic polymer inclusion membranes (IPIMs) with higher structural stability and ion transport capacity are found to have higher selectivity for separating and recovering cadmium ions. In this study, IPIMs were prepared using newly synthesized ionic liquids as ion carriers, and the optimized IPIM exhibited a high mass transport rate for cadmium recovery in iodide-containing acidic solutions.